Syria Civil War: Has Aleppo Massacre Begun? [VIDEO]

President Bashar al-Assad's forces step up bombardment on Syria's largest city

A defaced poster of Syria's President Bashar al-Assad is seen near garbage containers in Aleppo

President Bashar al-Assad's forces are conducting coordinated ground and air attacks on Aleppo, Syria's largest city, prompting fears that a massacre maybe under way. Scores of rebels belonging to the Free Syrian Army (FSA) have been killed or badly wounded. Several casualties have been reported across the city as bombardment in the rebel-controlled districts has escalated.

"Helicopters are participating in clashes at the entrance of Salaheddine district and bombarding it. There are also violent clashes at the entrances to Sakhour district," Britain-based Syrian Observatory for Human Rights told Reuters.

Salaheddine is the central district in Aleppo. Skirmishes were also reported in several other parts of the city.

An unverified video has emerged showing the intensity of the Syrian forces' shelling.

In an orchestrated move, military aircraft were seen flying at a low altitude over the region joined by ground forces and tanks closing in on the rebels.

"The most important (thing), which we have seen arise more recently, is the situation in Syria where what is happening is very important and very dangerous. There is a regime there that kills and massacres its own people," Erdogan said after meeting Prime Minister David Cameron in London.